Many electrical devices are constructed from a plurality of electrically conductive layers separated by one or more layers of electrical insulation material. For example, a capacitor is basically two metal plates separated by a layer of an electrically insulative material. In some instances, the electrically insulative material is air. In other instances, an actual electrically insulative material, such as Kapton or a similar material is used. Similarly, transformers include coils of wires that conduct electricity. A non-thermally conductive insulation material is placed around each wire in the coil to prevent individual wires in the coil from "shorting". The insulation layer prevents the flow of heat from the center of the transformer. This causes high core temperatures and reduced product life.
High temperatures can cause failure of an electrical component or reduced product life. Excessive operating temperatures can cause degradation of the insulation thereby enabling a short to develop between conductors previously separated by an insulative layer. As a result, there is always a need for an apparatus or material which can carry away heat, or cool, an electrical component and do it more efficiently. In the case of layered electrical devices such as transformers, inductors and capacitors, there is a need for a material that provides superior thermal transport and superior resistance to electrical current flow.
Smaller components are a constant goal of the electronics industry. Smaller components cost less and also result in smaller system packages. If a material and method that allows for more efficient dissipation of heat can be used, smaller amounts of that material need to be present to carry away the same amount of heat. Therefore, smaller components can be made. Electrical transformers can now be made in layers. The layers of the transformer are separated by an insulative material. If the insulative material is more effective at transferring heat, a thinner layer of insulative material can be used in forming the transformer. Thinner layers also result in lower core losses.
One way of building a multiple-device electronic component is to populate a common substrate with individual electrical components. In other words, discrete electrical components are attached to a substrate. Other electrical components, like capacitors or traditional transformers having coils wound about a core, mount directly to a substrate. The area of the substrate adjacent the electrical component may not be exposed to an ambient environment. The portion of the substrate next to the component may heat, causing the temperature to rise and possibly resulting in a failure. Thus, there is also a need for a material and method for making a substrate that efficiently removes heat from the individual components and delivers it to the chosen thermal "sink."